1. Field of the Invention
The present invention relates to a connector in which a pair of connector housings are coupled and connected together so as to establish an electrical connection, and more particularly to a connector having a coupling detecting mechanism for detecting whether or not the pair of connector housings are properly coupled together or a connector having a lock confirming mechanism for confirming the coupled posture of the pair of connector housings as well as the coupling detecting mechanism.
2. Statement of the Prior Art
The official gazette of Japanese Patent Public Disclosure (Kokai) No. 62-160674 (not examined) discloses a coupling detecting mechanism as a means for preventing the occurrence of partial coupling of a pair of connector housings in which the pair of connector housings are not properly coupled together because a distance by which the connector housings are actually being mated is too short. Namely, in a connector of this known type, a bar-like separate detecting spacer is mounted and locked on the upper side of one connector housing in a direction in which the one connector housing is coupled with the other connector housing, and this bar-like detecting spacer is then pushed forward after the two connector housings are coupled together to see whether the leading end of the detecting spacer "protrudes or not" from a detecting portion situated on the upper side of the connector in a coupled posture whereby whether the two connector housings are coupled properly or partially is visually judged.
In addition, there are many connectors having a coupled posture locking mechanism in which a resilient locking member provided on one of a pair of connector housings is mated with a locking pawl provided on the other connector housing for locking the two connector housings in a properly coupled posture.
With the above known connector having a coupling detecting mechanism, it is possible to effect a visual confirmation of the coupling condition of the connector by confirming the degree of protrusion of the detecting spacer. However, the connector of this known type has the following drawbacks.
In a connector for a wiring harness for an automobile, there are many cases in which connector housings are connected together in a limited space, and in a particular case, connector housings have to be connected together by feel, in which case the visual confirmation described above is not possible.
In the case of a connector in which the connector housings are not connected together due to oversight, it is impossible to detect an unconnected condition. In order to make it possible to effect a proper visual confirmation of the status of the detecting spacer, the connecting posture of the connector has to be limited such that the leading end of the detecting spacer may be easily seen.
In the case of a connector in which the associate connector housing is mounted on an apparatus, it is not possible to provide a detecting portion for detecting the leading end of the detecting spacer on the associate connector housing, and therefore it is not possible to adopt this coupling detecting mechanism.
In the coupled posture locking mechanism described above, visual or audible confirmation is not reliable when the connecting operation is conducted in a noisy place or where it is difficult to see the connected portion, since the coupling detecting depends on the sound resulting from the resilient lock piece engaging with the lock pawl or the external appearance of the coupled housings. When the locking mechanism is not properly engaged, a test for conductivity is positive so long as the terminals contact with each other. If such an improperly coupled connector is used in a car, conduction failure may be caused by vibration. Consequently, the locking mechanisms unreliable.
In addition, the official gazette of Japanese Patent Public Disclosures (Kokai) Nos. 1-109671 and 63-225480 (not examined) disclose applications of a photo-sensor used as a detecting and confirming mechanism for the connector coupling. These known mechanisms include a light-generating device which project light onto a confirmation aperture or mark formed on each of the connector housings to detect the connector coupling.
These mechanisms always require a light-generating device. In a wiring harness for a car in which the connector is disposed in various and complicated positions including many electric wires, it is often difficult to apply the light sensor to the connector. Thus, the detection and confirmation of the coupled connector using the light-generating device requires of complicated operations and is not many suitable for a modern mass production system.